Treatment of Atrial Septal Defect (ASD)
For secundum ASDs with right atrial and RV enlargement, percutaneous device closure is the first-line treatment, while all other ASD subtypes (sinus venosus, primum, coronary sinus) require surgical repair. 1, 2
Treatment Algorithm by ASD Type
Secundum ASD (Most Common)
Percutaneous Device Closure (First-Line)
- Indicated when right atrial and RV enlargement are present, regardless of symptoms 1, 2
- Requires Qp:Qs ≥1.5:1 with RV enlargement 2, 3
- Two FDA-approved devices in the United States: AMPLATZER septal occluder (for defects up to 38 mm) and HELEX occluder (for defects ≤18 mm) 1
- Success rate of 80% for secundum ASDs with currently available devices 4
- Associated with lower mortality, fewer complications, and shorter hospital stays compared to surgery 5
Surgical Closure (Alternative for Secundum)
- Reasonable when concomitant tricuspid valve repair/replacement is needed 1, 2
- Required when anatomy precludes percutaneous device use (defects >38 mm, insufficient septal rims) 1, 6
- Must be performed by surgeons with training and expertise in congenital heart disease 1
Non-Secundum ASDs (Mandatory Surgical Repair)
- Sinus venosus defects, primum ASDs, and coronary sinus defects must be repaired surgically 1, 2
- Percutaneous devices are not designed for these anatomic subtypes 1
Specific Clinical Indications for Closure
Class I Indications (Must Close)
- Right atrial and RV enlargement with or without symptoms 1, 2, 3
- Qp:Qs ≥1.5:1 with RV enlargement 2, 3
- Paradoxical embolism 1
- Documented orthodeoxia-platypnea 1
Class IIa Indications (Reasonable to Close)
- Asymptomatic patients with secundum ASD when right atrial and RV enlargement present, Qp:Qs ≥1.5:1, PA pressure <50% systemic, and PVR <1/3 systemic resistance 3
- During another cardiac procedure if Qp:Qs ≥1.5:1 and RV enlargement present 3
Class IIb Indications (May Consider)
- PA systolic pressure 50-67% of systemic AND PVR 1/3 to 2/3 of systemic resistance, requiring evaluation by pulmonary hypertension specialists 3
Absolute Contraindications (Class III - Do Not Close)
Critical hemodynamic thresholds that prohibit closure:
- Severe irreversible pulmonary arterial hypertension (PAH) with no evidence of left-to-right shunt 1, 2
- PA systolic pressure >2/3 systemic pressure 2, 3
- PVR >2/3 systemic vascular resistance 2, 3
- Net right-to-left shunt (Eisenmenger physiology) 3
Closure with established severe pulmonary vascular disease causes acute RV failure and death 3
Medical Management for Non-Operative Cases
Small ASDs (<5 mm without RV volume overload)
- No closure indicated unless paradoxical embolism present 3
- Repeat echocardiogram every 2-3 years to assess RV size, function, and pulmonary pressure 1
Atrial Arrhythmia Management
- Cardioversion after appropriate anticoagulation to restore sinus rhythm if atrial fibrillation occurs 1
- Rate control and anticoagulation if sinus rhythm cannot be maintained 1
- Concomitant Maze procedure may be considered for chronic atrial tachyarrhythmias during ASD closure 1
Critical Pitfalls to Avoid
Age-Related Considerations
- Do not assume small shunts are benign in older adults—acquired conditions (hypertension, coronary artery disease, valvular disease) increase LV stiffness and can convert previously insignificant ASDs into hemodynamically significant defects over time 1, 2, 3
- Older age increases risk of death and complications with percutaneous closure 5
Diagnostic Errors
- False-positive diagnosis can occur from septal dropout on 2D echo or misinterpretation of vena caval inflow as shunt flow—use contrast echocardiography or TEE to confirm 1
- Superior sinus venosus defects are frequently missed on transthoracic echo—if unexplained RV volume overload exists, perform TEE to evaluate atrial septum and pulmonary veins 1
Device-Related Complications
- Late complications include device thrombosis, cardiac erosion (most severe), atrial arrhythmias (most common), nickel allergy, conduction abnormalities, and device endocarditis 7
- Residual shunts are more common with percutaneous closure compared to surgery (RR 3.35) 5
Special Populations
Adult Congenital Heart Disease (ACHD)
- Assessment of hemodynamic abnormalities for potential repair of structural defects is mandatory as part of SVT therapy 1
- Patients with unoperated ASD who undergo surgery before age 25 have better long-term outcomes and lower incidence of atrial arrhythmias 1
- Catheter ablation of atrial arrhythmias associated with ASD repair has 93-100% acute success rates 1
Ebstein Anomaly with ASD